For quicker service, they could have quenched their thirsts at an adjacent store that also sells bubble tea. It had no customers.

Which is exactly as the protesters intended.

Digging in for the long haul against Hong Kong’s government, protesters are expanding their struggle from the streets to their wallets, weaponizing their spending power to punish businesses they deem hostile to their cause. The aim: to drive some firms under in the deepening recession gripping the crisis-hit city.

Guiding the consumer choices of tech-savvy protesters are apps that increasingly are color-coding businesses -everything from dentistry clinics and toy stores to dumpling restaurants and sex shops -into two categories: yellow for protest-friendly, blue for suspected opponents.

“Blue! blue!” protesters yelled outside the bubble tea shop they shunned during a rally this month that marked the half-year milestone for their movement.

The protests started in June to voice opposition to now-withdrawn extradition legislation and have morphed into what demonstrators say is a full-blown fight to safeguard Hong Kong’s freedoms, unique among China’s cities. Months of clashes with riot police who have fired 26,000 tear-gas and rubber-baton rounds and arrested more than 6,100 people are radicalizing legions of youths, upending the city’s economy, and splitting families, work colleagues, friends and citizens into two entrenched camps.

Even employees of the supposedly “blue” bubble tea store, wearing face masks like many of the demonstrators, advised them not to shop there, saying the company wasn’t sympathetic to the protest movement.

“It stands for the police,” protester Natasha Chan said, clutching a grapefruit and lemon tea purchased instead from the “yellow” Happy Holidays drinks store next door. “We chose not to shop from the blue side.”

Protesters believe that by boycotting supposedly pro-establishment businesses, they can help shift the balance of power and wealth in the semi-autonomous Chinese territory.

Much of the city’s $345 billion economy and political influence are concentrated in the hands of magnates and enterprises linked to or supportive of mainland China and its Communist Party-led government -the ultimate boss of Hong Kong leader Carrie Lam.

Protesters also say that shopping “yellow” is another way to make their voices heard in the absence of direct elections for government leaders. Protesting with their wallets also enables people who can’t always join street rallies, including those who fear being fired by pro-China employers, to otherwise contribute to the movement.

Before marching in the rally for the half-year milestone, accountant Nakata Law lined up for 15 minutes to support a snack shop that has donated to the protesters’ cause, buying its steamed dumplings and gluey rice pancakes. A poster on the Jar Gor eatery says: “Support Yellow. This store has been rated as a true Hong Konger merchant.”

“Most of the economy is controlled by China,” Law said. “The citizens’ view is that if we do not have our own economic circle in Hong Kong, we cannot support our protests to keep carrying on.”

In the opposing camp, Phyllis Li, a systems analyst who believes protest violence has gotten out of hand, says she now deliberately chooses to eat at restaurants that protesters boycott “because it is not fair to them.”

“And because it’s safe for us, too, because they don’t go,” she said.

Anecdotal evidence suggests protester boycotts are biting the bottom lines of some targeted businesses. Passenger traffic on Hong Kong’s Mass Transit Railway dropped by a quarter in October and November. Transport disruption from protests caused some of the plunge. But some protesters are also refusing to use the network they suspect of colluding with police.

Edith Leung, an architectural assistant, says she hasn’t ridden the MTR since August, taking buses instead. Some protesters say they’re so determined not to commute by train, they’re getting up early to leave extra time for lengthier bus journeys.

“Sometimes we feel like it’s just a drop in the ocean,” Leung said. “But when more people do it, we become the ocean.”

But some businesses finding themselves on the “blue” side of the city’s hardening divide say they’re being unfairly targeted.

Martin Khan says the Capital Cafe he runs with his brother on Hong Kong Island has lost half of its customers since accusations appeared online suggesting that they oppose the movement.

Khan says not only is that untrue, but that the “blue” tag apps have assigned to their eatery is based on unfounded suspicions of a supposed link between them and a singer, Alan Tam, who has spoken publicly in support of police. Their cafe used to serve a toast, with melted cheese and shavings of black truffle, that they named after Tam, but has now removed it from the menu.

“Honestly, we have no connection with him,” Khan said. “It’s really not fair.”

The developer of one of the apps, which uses crowd-sourced information to distinguish supposed blue businesses from yellow ones, says he fears he is contributing to a politically motivated witch hunt -like those the Communist Party has unleashed repeatedly across the border in mainland China.

“I’m very, very worried,” said the developer, Chi Ho Leung. “It’s like the Cultural Revolution.”

His app, Hong Kong Shops, lists 1,700 stores, divided largely into yellow and blue. But Leung said he has neither the money nor time to verify the accuracy of information he found online about the businesses’ supposed pro- or anti-protest leanings. He says stores can email him to request a change of color if they feel they’ve been inaccurately categorized.

But his app also invites users to name and shame stores they feel aren’t supportive, offering categorizations including “deep blue” for businesses suspected of supporting police abuses and gray for those “selling out the people.”

Leung says that because commercial rents are so expensive in Hong Kong, his hope is that boycotted stores may not survive the recession.

Although users say they regard the apps only as rough guides and not bibles, they’re building the act of protest shopping into daily habits. It is just one example of how the protest movement is altering the fabric of Hong Kong life and awakening citizens politically, even if it hasn’t succeeded in making Beijing and Hong Kong leaders bend to calls for full democracy and other demands.

Franklin Lau, who works in public relations, says he now uses blue/yellow apps and other online pointers, including Facebook posts, on a regular basis. He says he wants to “draw a line” between himself and any business that opposes the protests. He also wants to avoid the stigma that protesters are attaching to those who still shop ”blue.”

“If you say, ‘Well, I had a meal in a blue restaurant just now’ ... you tend not to like share (that) news with your friend,” Lau said. “You don’t want to have any association or connection with them.”